Thoughts without content are empty, intuitions without concepts are blind.

One is not rich by what one owns, but more by what one is able to do without with dignity.

The hand is the visible part of the brain.

Reason can never prove the existence of God.

Seek not the favor of the multitude; it is seldom got by honest and lawful means. But seek the testimony of few; and number not voices, but weigh them.

The more we come in contact with animals and observe their behaviour, the more we love them, for we see how great is their care of the young.

Experience without theory is blind, but theory without experience is mere intellectual play.